Borrowings - Additional Information (Detail) - USD ($)	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Line of Credit Facility [Line Items]
Line of credit expiration month and year	2020-07
Line of credit, interest rate description	interest rates equal to M&T’s current prime rate or the then-current LIBOR rate plus 2.25%
Percentage commitment fee	0.15%
Manufacturers and Traders Trust Company [Member]
Line of Credit Facility [Line Items]
Line of credit facility remaining borrowing capacity		$ 30,000,000
Line of credit covenant description	The credit agreement requires our compliance with certain covenants. These covenants include minimum levels of our net worth, leverage ratio, statutory surplus and the A.M. Best ratings of our insurance subsidiaries. In addition, Atlantic States has guaranteed our payment obligations under the new credit agreement. We complied with all requirements of the credit agreement during the three months ended March 31, 2020.
FHLB of Pittsburgh [Member] \| Atlantic States [Member]
Line of Credit Facility [Line Items]
Right to request for extension of credit agreement with Manufacturers and Traders Trust Company	$ 21,278,660
Outstanding advances	35,000,000
Federal home loan bank, fixed rate advances	35,000,000
Pre-Payment of Penalty	176,000
Revolving Credit Facility [Member] \| Manufacturers and Traders Trust Company [Member]
Line of Credit Facility [Line Items]
Right to request for extension of credit agreement with Manufacturers and Traders Trust Company		$ 30,000,000
Line of credit facility amount outstanding	$ 0
Debt Instrument variable interest rate spread	2.25%
Line of Credit [Member] \| FHLB of Pittsburgh [Member] \| Atlantic States [Member]
Line of Credit Facility [Line Items]
Interest rate on advances	1.74%
Subordinated Debentures [Member]
Line of Credit Facility [Line Items]
Debt instrument stated interest rate	5.00%
Subordinated Debentures [Member] \| West Bend Mutual Insurance Company [Member]
Line of Credit Facility [Line Items]
Surplus note	$ 5,000,000
Subordinated Debentures [Member] \| FHLB of Pittsburgh [Member] \| Line of Credit [Member] \| March 2021 Due [Member]
Line of Credit Facility [Line Items]
Outstanding advances	$ 50,000,000
Interest rate on advances	0.83%

Line of credit facility expiration month and year.

No definition available.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

Description of minimum financial levels (for example, tangible net worth and working capital) and achievement of certain financial ratios (for example, working capital ratio and debt service coverage ratio), and adherence to certain clauses which generally require or restrict certain actions (for example, entering into a debt arrangement with equal or greater seniority, and selling or discontinuing a certain business segment or material subsidiary) to be in compliance with the covenant clauses of the debt agreement. May also include a discussion of the adverse consequences that would result if the entity violates or fails to satisfy the covenants.

+ References

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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- Definition

Amount of advances from the Federal Home Loan Bank (FHLB).

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-Section 45
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- Definition

Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

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- Definition

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank) with fixed interest rate.

+ References

No definition available.

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- Definition

The fair value of line of credit assumed in noncash investing or financing activities.

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-Name Accounting Standards Codification
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- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

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- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

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- Definition

Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

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- Definition

Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

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- Definition

Financial instruments issued by insurance entities (surplus notes) that are includable in surplus for statutory accounting purposes as prescribed or permitted by state laws and regulations that are liabilities of the issuer.

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